I'm very disappointed in this pillow. I've used a pillow of similar shape, but, frankly, much lower price, for several years. I have a degenerating disc and arthritis in my neck. The thicker side is meant to fit under my neck so there is no "bridge" between my head and shoulders. It feels good when I first lie on it, but I found that this pillow just goes flat beneath my head after about 10 minutes, and I feel as if I may as well be sleeping without any pillow at all. I do expect memory foam to give as soon as it's warmed by body heat, but the foam in this pillow collapses too far and too quickly. After sleeping on it for 3 nights, my neck and shoulders became painful. I got up in the middle of the 3rd night, got my old memory-foam pillow, and switched back to it. The texture of this pillow is like a marshmallow. I don't know what else to compare it to. I've never seen a foam quite like this before. I'm surprised that it can be called "medium density." The width of the pillow is so narrow that a regular size pillow case just flops around on it. It's a little long for a standard size case and too short to need a king-size case. Either one is too big overall. The pillow smells quite strongly of something chemical or plastic, at first. I aired it out for about a week before I tried to sleep on it. As long as my face is away from it (I can only sleep on my back) the smell doesn't bother me, but, if I wanted to sleep on my side with my nose close to the pillow, I think I'd find the smell too obnoxious to tolerate. I live in a hot climate, so I thought the cool gel might be nice at least in the summer, because memory foam is known for heat retention, but, at this point, all it does is feel a bit clammy for a few minutes, then that cool sensation goes away. The construction of the pillow and its cover seems fine, although I've never seen a pillow where the zipper runs lengthwise down the middle of the pillow, before. Because of the marshmallow texture of this pillow, that may be necessary to get the pillow in and out of the cover without a big battle. I would not recommend this pillow except to someone who likes to sleep on virtually no pillow at all or perhaps someone who is very small. It is definitely not a side-sleeper's pillow, and it is definitely not for me. I don't see an option to return it just because I don't like it, but, if I can find a way to return it, I'm going to do so because, for me, it was just a waste of money.